Two protocols have been developed and approved (91-DK-133) and 91-DK-97) to use positron emission tomography (PET) and nuclear magnetic resonance spectroscopy (NMR) to study insulin and IGF-1 action in patients with insulin resistance. Due to technical problems, the NMR investigation in 91- DK-133 was discontinued at the time of the last protocol review. In the last year no patients were studied using this methodology. A protocol is being developed to study pre-diabetic Pima indians which will include this technique. One patient with IGF-II induced hypoglycemia from adrenocortical carcinoma was studied using PET in the last year.